Mango (Mangifera indica L.) is an important tropical fruit with a delicate taste, pleasant aroma, and high nutritional value. In recent years, with the promotion of the rural revitalization strategy and the development of the poverty alleviation industry, China has gradually become an important mango producer. However, the short shelf life of mango fruit, the difficulty in regulating the postharvest quality, and the lack of preservation technology are the main problems that need to be solved in China‘s mango industry. In this paper, the physiological changes and mechanisms of mango during postharvest ripening were summarized, including sugar and acid changes, pigment synthesis and accumulation, and aroma formation and accumulation. The physical, chemical, and biological technologies (such as endogenous phytohormones, temperature, light, chemical preservatives, and edible coatings) commonly used in the regulation of mango postharvest ripening and their action principles were emphatically expounded. The shortcomings of the existing mango postharvest ripening regulation technology and physiological mechanism research were analyzed in order to provide a reference for the industrial application and development of mango postharvest.

The mechanism by which LED red light irradiation regulates postharvest banana ripening was evaluated in this study by the continuous irradiation of banana fruits at the mature-green stage. In this study, a self-developed LED banana fresh-keeping container lid was used to continuously irradiate the immature banana fruit. The light wavelength was 655.0 ± 1.0 nm, the light intensity was 800.0 ± 10.0 LX, and the height between the LED lamp and the fruit was 15.0 ± 0.5 cm. Bananas stored under dark conditions were used as the negative control group, and bananas stored under dark conditions after spraying with 500.0 mg/L ethephon diluent were used as the positive control group. Changes in physiological parameters related to postharvest banana ripening, such as the respiration rate, ethylene release, texture, color, carotenoid content, chlorophyll content, adenosine triphosphate content, and energy metabolism-related enzyme activities, were measured during 8 days of storage at 20.0 ± 0.1 °C to analyze the key factors determining postharvest banana ripening in response to red light. The red light-irradiated bananas had higher total color differences and higher rates of chlorophyll degradation and carotenoid synthesis than those of the ethephon-treated group during the storage period. Red light irradiation promoted banana fruit ripening and senescence mainly by promoting carotenoid synthesis, capturing absorbed light energy, accelerating energy metabolism, effectively enhancing the activities of the respiratory and energy metabolism-related enzymes H⁺ adenosine triphosphatase, Ca²⁺ adenosine triphosphatase, succinate dehydrogenase, cytochrome C oxidase, and malic enzyme, and promoting organic acid degradation. In conclusion, LED red light can be used as a new physical ripening technology for bananas, with a similar effect to that of traditional ethephon treatment.

This study aimed to investigate that rapid high-temperature treatment (RHT) at an appropriate temperature could accelerate callus formation by effectively promoting the necessary metabolic pathways in sweet potato callus. In this study, the callus of sweet potato was treated with heat shock at 50, 65, and 80 °C for 15 min. The callus formation was observed within 1, 3, and 5 days, and the accumulation of intermediates in the metabolism of phenylpropane and reactive oxygen species and changes in enzyme activities were determined. The results showed that appropriate RHT treatment at 65 °C stimulated the metabolism of reactive oxygen species at the injury site of sweet potato on the first day, and maintained a high level of reactive oxygen species production and scavenging within 5 days. The higher level of reactive oxygen species stimulated the phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase and cinnamate-4-hydroxylase activities of the phenylpropane metabolic pathway, and promoted the rapid synthesis of chlorogenic acid, p-coumaric acid, rutin, and caffeic acid at the injury site, which stacked to form callus. By Pearson’s correlation analysis, catalase (CAT), PAL, and chlorogenic acid content were found to be strongly positively correlated with changes in all metabolites and enzymatic activities. Our results indicated that appropriate high-temperature rapid treatment could promote sweet potato callus by inducing reactive oxygen species and phenylpropane metabolism; moreover, CAT, PAL, and chlorogenic acid were key factors in promoting two metabolic pathways in sweet potato callus.